Rotary earth boring drill



July 7, 1936.

c. E. RE ED ROTARY EARTH BORING DRILL Original Filed May 22, 1933 3 Sheets-Sheet l ERegd,

July 7,1936. E

ROTARY RARTR BORING DRILL 5 Sheets- Sheet 2 Original Filed May 22, 1933 v QZarpne ElReed arty/M 64 July 7, 1936. c. E. REED 2,047,115

ROTARY EARTH BORING DRILL Original Filed May 22, 1933 3 Sheets-Sheet 3 Clacenc EReed,

UNITED fiTAThS rat fiiiiimlllifi ROTARY EARTH WWRING lillitllLL @larencc E. Reed, Wichita, Karla, assignor to Chicago Pneumatic Tool Company, New Torlr, N. TX, a corporation or New Jersey Application May 22, 1933, Serial No. 672,317 Renewed December 2'3, 1935 55 @laims; (till. 255-471) The invention concerns rotary earth boring fate about spindle portions 9 and 9a: which are drills of the type carrying a plurality of rotary eccentric to each other but integral with each toothed cutters for cutting the formation at the other, the arrangement being such that the bottom of the hole. The cutter organization intoothed peripheries of these two cutters where eludes side cutters spaced about the drill 120 they contact the bottom of the hole are in the 5 apart with a plurality of cutters whose axes are same horizontal plane. The spindle t bears in in the same radial plane with the axis of one member ta mounted in the cutter carrier ii. of said side cutters. It has a socket receiving a spindle portion We The invention consists in the features and on which the roller cutter is ismounted. This n combination of elements hereinafter described spindle Mia is integral with another spindle porand pointed out in the claims. tion lb on which roller cutter 5a is mounted. In the drawings d I There is a flange ind integral with and between Figure 1 is a vertical sectional view of the the spindle portions We and W1), which flange drill, this'section being taken on line ii of presents thrust bearing surfaces at its side faces Fig. 3 in the direction of the arrow. for the roller cutters tar and tar and for the roller Fig. 2 is a vertical sectional view of Fig.3 on bearings on which the said cutters revolve. line 2-2, this section being from the vertical The spindle portions lite. and Nb are ec-' axis of the drill outwardly. centric to each other and their axes are at an Fig. 3 is a bottom plan view of the drill, acute angle to each other. The side roller tr Fig. 4 is a sectional plan view on line ll-t of turns on roller hearings on a spindle M which 20 Figs. 1 and 2. has a flange lib socketed to receive the spindle Fig. 5 is a side view of the carrier for the roller p r n l s flan e pr n a its si faces cutters looking in the same direction as in Fig. l. thrust ring surfaces for the roller cutters tar Fig. 6 is a side elevation of the roller cutter and and t e ro le bearings Ma;

WFFWH carrier looking from the right of Fig. 5. The sp d Ill bears in a bush ng M hav n a 25 Fig. 7 is a bottom plan view of the roller cutter flan e Ma furnishin a th ust bearin sur a e carrier of Fig. 5. for the roller cutter ta: and the ball bearings i to.

Fig, 8 is a, vertical sectional view f the bit The carrier or frame memberin which the roller head viewed in the ame directi a i Fig, 1, cutters are mounted is marked t. It constitutes Fig. 9 is a bottom plan view of the bit head. pa t of t roller cutter unit rem'ovably mounted 20' Fig. 10 is a side elevation of the bit head. in the bit head- ThiS as b a s in As indicated in the bottom plan iew, Fig, 3, which are mounted the spindle 937, the block 90; the roller cutter organization includes three side in which spindlest and We bear. all as s ow cutters which define the size of the hole. These in g. 1.

side cutters are marked in said figure ix, 6m, and AS Shown in 2, this cu e ca er frame 35.

fly. Their axes are in vertical planes radiating also has a Socket for the flange Of a p e B from t vertical axis of t p 120 apart. which supports the side roller cutter la: and the Adjacent .the vertical axis of the drill and on roller bearings s flange p nts an nd the opposite side thereof from the side cutter 6.1: thrust bearing surface On its Side face e is arranged on a horizontal axis a comparatively roller cutter la: and the roller bearings 8b. The 40 small diameter cutter 3x. Adjacent this cutter spindle .8 bears in another 01,16 0f the bushings and further from the axis there is another cutthe flange 14a of which forms an end thrust ter 3y oflarger diameter rotating about a horihearing for the side roller cutter s. zontal axis parallel with the horizontal axis of The third Side r0118! Cutter is ted o a the cutter 31:. Between the cutter 3a: and the Spindle like that cutter S p d in'like 45 side cutter 6x, and with their axes in the same manner by the cutter carrier member 6, as will vertical plane in which lie the axes of the cutbe clear from Fig. 3. Showing a bottom P V w ters 3x and 6x, are roller cutters 4a.- and 5.1;, of the drill. -All of these side roller cutters are 7 These cutters 4x, 5x, and 61: have their axes inon axes inclining upwardly and outwardly in reclining upwardly and outwardly and these axes spect to the vertical axis .r:c of the drill, and 50 are at acute angles to each other and to the the angular relation of these axes to the vertical axis of the side cutter 6x so that these roller cutaxis of the drill is the-same in respect to each ters rotate in planes convergent upwardly to side cutter. The angular relation of the cutters wards the vertical axis of the drill indicated at 4x and 51: differs from each other and from the 55 :c-z in Fig. 1. The roller cutters 3m. and 811 roside cutters so that all or these cutters just men- 55 tioned are in convergent relation upwardly towards the vertical axis of the drill. The cutter carrier is mounted in the bit head i which has means at 2 for attachment removably to the drill pipe or stem. The bit head has a socket 2a which receives the upper end of the cutter carrier 6, this projection being of hollow cylindrical form. The bit head has a downwardly flaring recess 3 at a point below the socket just mentioned, said recess being defined by depending walls having downwardly and outwardly inclined inner faces 3. These depending walls have notches 5 at their lower ends open downwardly and in these notches the bushings i l find bearings when the cutter unit is thrust up into place. The cutter carrier 6 is held to the bit head by taper bolts 6b passin through exterior bosses E2 of the bit head and through wings or lugs ta on the carrier projecting through slots or notches id of the bit head which notches open downwardly, so that by thrusting the cutter carrier upwardly and axially of the bit head, the said lugs orwings to will enter said notches or slots 1 a and willpresent the openings of the lugs to into alignment with the openings through the bosses it so that the taper bolts can be inserted to draw the cutter carrier up into place, as shown in Figs. 1 and 2, with its upper end seated against the top of the socket in the bit head with suitable packing forming a seat. Adjacent the lugs l2 of the bit head there are recesses 52a on the outer side of the bit head to allow the ready insertion of the taper bolts into place. As shown in Fig. i, two taper bolts are sufiicient to hold the carrier in place. These bolts are arranged at an angle to each other and on radii 120 apart.

The bolts are drawn into place and held by suitable nuts, as shown. By removing these bolts, the entire cutter organization may be removed and replaced.

The organization described cuts the entire area at the bottom of the hole. All the cutters rotate independently. It will be noted that the crests of the teeth on each cutter, if projected do not intersect at the bit head axis, and that the teeth therefore do not have a true rolling motion upon the ground.

Considering the group shown in Fig. 1, it will be noted that the cutters are of diii'erent diameter and thus progress in size from the vertical axis outwardly. All the side cutters are of the same diameter. An organization is thus presented in which the cutters are capacitated to do the amount of work required according to their distance from the vertical axis of the drill, the outermost cutters, i. e., the side cutters, having to do the most cutting, being in plural number to supplement each other in performing the work along the zone of largest diameter.

The upwardly and outwardly inclination of the axes of the cutters makes an inverted arched arrangement of cutters. Welding of parts of the spindles and their supporting members may be resorted to where necessary.

The cutter carrier 6 has recesses 611 for the cylindrical cutters 3m, 39. The cutter carrier is provided with suitable passages for directing flushing fluid to the cutters.

The depending wall portions of the bit head are shown at Ic. These have vertical outer faces and they also have the downwardly flaring inner faces 4 before mentioned, and the open notches 5.

These wall portions lc of the bit head project laterally in respect to the upper stem portion of the bit head as shown more particularly in Figs. 1

and 9 though well represented in Figs. 1, 2, 8, and 10.

It will be understood, of course, that my broad idea is not limited to the exact details shown in the drawings and described in these specifications, but that changes may be made therein within the scope of the appended claims.

Certain features relating to the bearing and spindle structure for the cutters, and the cutter arrangement disclosed herein, are claimed in 00- 1 pending application 671,384, filed May 16, 1933.

I claim:

1. An earth boring drill having side roller cutters spaced apart at different angular positions about the axis or" the drill and with their axes 1,

respectively in different diametrical planes, 2. cutter near the vertical axis of the drill and a cutter arranged between one of the side cutters and the cutter near the axis of the drill, all contacting the bottom of the hole below the drill, all of the 2 side cutters tracking each other and cutting both beyond and within the projected side of the drill head, substantially as described.

2. An earth boring drill according to claim 1 in which the cutter near the axis of the drill roi.

tates about a horizontal axis and the other cutters rotate about axes inclining upwardly and outwardly, the said intermediate cutter rotatin about an axis at an acute angle to the axis of the adjacent side cutter.

3. An earth boring drill according to claim 1 in which two rotary cutters arranged between the side cutter and the cutter near the axis of the drill head, the axes of all the cutters lying in the same vertical plane having their axes at acute :1 angles, to each other.

4. An earth boring drill having a bit head and a roller cutter organization comprising a carrier removably attached to the bit head, side cutters on said carrier at degrees apart about. the circumference of said bit head, and on upwardly and outwardly inclined axes, a plurality of cutters rotating about horizontal axes and of different diameter, said plurality of cutters being on the opposite side of the vertical axis of the 4 drill from one of the side cutters, and with their axes in the same vertical radial plane with the axis of said one of the side cutters, cutters between the plurality of cutters and said one of the side cutters on upwardly and outwardly inclined axes at acute angles to each other and to the upwardly inclined axis of said one of the side cutters, and in the same vertical plane therewith, each cutter being of larger diameter in respect to the next cutter nearer the vertical axis 5.

of the drill, substantially as described.

5. A bit head for a rotary earth boring drill having means for attachment to a drill stem, 9. socket and a flaring recess below said socket defined by depending wall portions in different 6 angular positions about the circumference of the bit head, said wall portions each having a notch in its lower end, said wall portions being separated from each other by slots or notches opening downwardly and extending through the socket 0 wall and disposed at different angular positions about the bit head, and means for holding bolts in angular positions relative to each other with their axes intersecting for securing a cutter carrier to the bit head, said means comprising bosses 7 exterior to and carried by the wall of the bit head and having openings, the axes of which are substantially tangential to the wall of the bit head, substantially as described.

6. A cutter organization for an earth boring 7 drill comprising a carrier member, having side roller cutters disposed about the same at 120 apart on spindles projecting outwardly and upwardly relative to said carrier, one of the side cutters having a plurality of cutters associated therewith, whose axes are in the same vertical radial plane with the axis of said side cutter,

'said cutters being of different diameters, said carrier having wings or lugs projecting therefrom at different angular positions about the same, said lugs-being adapted to fit into slots of a bit head, substantially-as described.

'7. An earth boring drill comprising a bit-head having a stem portion with means for attaching the same to a drill pipe or stem and having a lower body portion with a socket and a downwardly flaring recess defined by wall portions spaced apart 120, and a plurality of downwardly opening slots in angular relation to each other and with perforated lugs adjacent said slots on the outer side of the bit head and with recesses in the outer side of the head adjacent said lugs, but on the opposite sides of the lugs from said slots, and a roller cutter unit comprising a carrier member having an upper portion to fit the socket in the bit head and wings or lugs disposed in different diametrical planes to fit the corresponding angularly disposed slots in the head, both arranged in angular relation to each other to secure the wings of the carrier to the lugs of and outwardly inclined spindles seated in notches in the wall portions of the bit head, roller cutting means mounted on the carrier near the vertical axis of the bit head and roller cutting means arranged intermediate one of the side cutters and the said cutting means near the vertical axis of the drill, said intermediate cutting means being mounted on an upwardly and outwardly inclined spindle, the axis of which is at an acute angle to the axis of the side cutter, the axes of the said side cutter, the intermediate cutting means and the cutting means near the vertical axis of the drill being in the same vertical radial plane, substantially as described.

8. A rotary drill for earth boring according to claim 7 in which the intermediate roller cutting means and the adjacent side cutter are on one side of the vertical axis of the drill, and the cutting means near the said vertical axis is on the opposite side thereof. I

9. A roller bit comprising three side cutters whose axes incline downwardly and inwardly t0- wards the bit axis, said cutters being disposed in different angular positions about the bit head and with their axes in non-coinciding vertical planes, and a series of cutters having their axes all in the same vertical plane as the axis of one of the side cutters, said series extending from the said side cutter across the bit axis cutting the bottom of the hole on both sides of the bit axis inwardly of the path of the side cutters.

10. An earth boring drill according to claim 9 in which the said series have an axis perpendicular to the bit axis and another axis inclined to the bit axis.

11. An earth boring drill according to claim 9 in which some of the cutters of the said series are in planes at an acute angle to the plane of the' side cutter, the axis f which is in the' same vertical plane as the axes of the series.

12. An earth boring drill bit comprising .three side cutters whose axes incline downwardly and inwardly towards the bit axis, said side cutters being spaced 120 apart and all tracking each other and cutting clearance beyond the side of the bit head, -and a series of cutters for cutting the bottom of the hole inwardly of the path of the side cutters, the cutters in said series having their axes all in the same vertical plane as the axis of one of the side cutters, one cutter of said series being disposed on the side of the bit axis opposite said last-named side cutter and having an axis perpendicular to the bit axis.

13. An earth boring drill according to claim 12 in which the said cutter on the opposite side of the bit axis from the last named side cutter in a plane parallel to the bit axis ispositioned adjacent to the bit axis.

14. A roller boring "drill comprising three side roller cutters having axes inclined in radial planes and a cutter group positioned for cutting at both sides of the drill axis, said group having axes all in the same vertical plane as the axis of,one of the side cutters, all of the side roller cutters being of equal diameter, disposed 120 apart and tracking each other, and said cutter group lying on opposite sides of the drill axis.

15. A roller boring drill comprising a bit head, a carrier insertable into said bit head, and three spindles projecting outwardly from said carrier and received by notches in the bit head, three side roller. cutters mounted on the carrier at different points about the said carrier, an inner group of cutters, the axis of one of the side cutters being in substantially the same vertical plane as said inner cutter group, said group comprising roller cutter means on an axis inclined to and other roller cutter means on an axis perpendicular to the axis of the bit head.

16. An earth boring drill comprising a body or carrier member, three spindles projecting outwardly from said member for supporting thereon roller cutters, and an additional cutter spindle mounted in a recess in the lower end of said member.

17. A roller cutter unit for earth boring drills comprising a body portion eccentrically positioned between the cutters, said body portion having two sides that incline upwardly and inwardly towards the axis of the unit symmetrically, and another side also inclining upwardly and inwardly towards the axis of the unit, inclined spindles of unequal lengths projecting outwardly and upwardly from said sides, and a recess in the lower face of said body portion receiving other cutter means to one side of and adjacent the vertical axis of the drill, and rotating on an axis perpendicular to said drill axis, and in which recess the said roller cutter means rotates.

18. A roller bit comprising three side roller cutters whose axes incline downwardly and inwardly towards the bit axis said side cutters tracking each other at the side of the bore hole wardly towards the bit axis, said side cutters tracking each other at the side of the bore hole and a series of cutters having their axes all in the same vertical plane as theaxis of one of the side cutters, said series cutting the bottom of the hole inwardly of the path of the side cutters, said series having an inclined cutter on one side of the bit axis and a cutter in a plane parallel to the bit axis on the other side of said axis, said cutter in a plane parallel to the bit axis being adjacent to the bit axis.

20. An earth boring drill having a drill head, a series of rotary toothed cutters at its lower face with their axes in the same vertical diametrical plane, one of said series being a side roller cutter for cutting an annular area at the bottom of the hole adjacent the side wall thereof both outside and inside the projected plane of the side of the drill head, and another of said series being on the side of the vertical axis of the drill opposite to.

that upon which the said side cutter is located, said series of cutters cutting the entire area at the bottom of the well, and additional side roller cutters whose axes lie in different vertical diametrical planes from each other and from the vertical plane in which the axis of the first mentioned side roller cutter lies, there being one of said additional side roller cutters at each side of the vertical diametrical plane in which the axes of the first mentioned series of cutters lie, all the side roller cutters tracking each other, substantially as described.

21. An earth boring drill according to claim 20 in which the cutter of said series on the opposite side of the vertical axis of the drill from the first mentioned side roller cutter is arranged adjacent said vertical axis, and is mounted in supporting means mainly located on the same side of said vertical axis therewith.

22. An earth boring drill comprising a bit head, a group of side roller cutters of substantially equal diameter tracking each other and disposed in different diametrical vertical planes about the bit head on axes inclining downwardly and inwardly to the vertical axis of the drill, and rotary cutter means arranged inwardly relative to and axially in the same vertical, diametrical plane with the axis of one of the inclined side cutters, said inwardly positioned rotary cutter means being of reduced diameter as compared with the diameter of its associated side roller cutter and extending substantially to and beyond the vertical axis of the drill, and together with said associated side roller cutter cutting the entire area at the bottom of the hole, said group of side roller cutters being spaced apart at substantially whereby the inwardly disposed cutter means of reduced diameter and the associated side cutter will lie in the vertical diametrical plane passing midway between the other two side roller cutters, substantially as described.

23. A roller cutter unit for earth boring drills comprising a body having three sides that incline upwardly and inwardly towards the axis of the unit, spindles projecting therefrom whose axes are inclined in radial planes, side roller cutters on said spindles, other roller cutters in a recess in the lower face of the said body, and another roller cutter means positioned to disintegrate the area between the path of the side cutters and the path of the cutters in the recess, all of the thrm side cutters tracking each other, and said last mentioned roller cutter being mounted substantially on one of said inclined spindles of a side roller cutter.

24. A roller boring drill having a bit head with a recess in its lower end and a socket above the recess with a slot extending through the wall of the socket, a carrier member having a portion to fit the recess and portions to fit the socket and slot respectively and three equal diameter tracking side roller cutters mounted in the carrier with the axis of one of the side cutters in substantially the same vertical plane as the axes of a centrally positioned cutter group, said group comprising a roller cutter having its axis inclined to the vertical axis of the drill, and another cutter having its axis perpendicular to the said drill axis, said two last mentioned cutters being on opposite sides of the drill axis.

25. An earth boring drill comprising a drill head, a cutter carrier member with means for connecting the carrier member to the head, three spindles projecting outwardly from said member for supporting thereon roller cutters, said spindles at their outer ends bearing in the bit head and being 120 degrees apart, said member having a recess in its lower face and roller cutter means in said recess.

26. An earth boring drill comprising a bit head, a plurality of roller cutters including a side cutter mounted on the head to rotate on axes in the same transverse-vertical plane but at different angles of inclination to the vertical axis of the drill, and additional side cutters whose axes are disposed in different vertical planes from each other and from the vertical plane of the axes of the first-mentioned cutters, all the side roller cutters being of the same diameter and tracking 30 each other.

27. An earth boring drill comprising a bit head, a set of roller cutters including but one side outter together with other cutters, all mounted on the bit head to rotate on axes in the same vertical plane which includes the bit head axis and on both sides of the said axis and adapted to cut the entire area at the bottom of the hole. and additional cutters each mounted to rotate about an inclined axis in a different diametrical plane from the plane first-mentioned and adapted to cut the peripheral area at the side of the hole, all the side roller cutters being of the same diameter and all tracking each other.

28. An earth boring drill comprising a bit head, a set of roller cutters mounted upon the head to rotate on axes in the same vertical plane which includes the bit head axis and on both sides of the said axis and adapted to cut the entire area at the bottom of the hole, said set of cutters including but one side cutter, and two additional side cutters,.the three side cutters being equally spaced about the periphery of the bit head. all of the side cutters being of the same diameter and tracking each other.

29. An earth boring drill comprisinga drill bit head, a carrier and side roller cutters mounted thereon, and tracking each other, the axes of said roller cutters being disposed in three vertical planes 120 degrees apart, a plurality of cutters positioned on opposite sides of the vertical axis of the drill with their axes in the same vertical plane with one of the side cutters and together with said side cutter being arranged to cut the entire area at the bottom of the hole, at least one of said roller cutters being cylindrical.

30. An earth boring drill comprising a drill bit head and side roller cutters mounted therein, the axes for said side roller cutters being disposed in three vertical planes 120 degrees apart and being arranged to track each other at the side of the bottom of the hole, two or more other roller cutters mounted on the head to rotate on axes in the same vertical plane with one of the side cutters and on diflzerent sides oi. the bit axis,

all of the cutters being independently rotatable, said two or more other cutters and the last mentioned side cutter cutting the entire area-at the bottom of the hole.

31. In an earth boring drill having a bit head, a roller. cutter organization comprising a plurality of rotary cutters arranged side by side in a group and respectively in planes convergent upwardly in the bit head and in which the end cutters of the group are axially in the same diametrical planev of the bit head, and in which a cutter of the group is arranged substantially at the vertical axis of the drill on a horizontal axis, substantially as described.

32. The combination in an earth boring drill of a head, side cutters convergent upwardly towards the vertical axis of the drill at corresponding angles, and arranged on axes inclining downwardly and inwardly towards the axis of the bitscribed.

33. A rotary toofhed cutter unit for earth boring drills compris ng a side cutter inclining upwardly and inwardly towards the vertical axis about whichthe unit rotates, a cutter on a sub stantially horizontal axis adjacent said vertical axis and a cutter intermediate the said cutters and of smaller diameter than the side cutter and on an axis at an acute angleto that of the side cutter, whereby said intermediate cutter con verges upwardly relative to said side cutter, said cuttersbeing independently rotatable, substantially as described.

3A. A roller cutter unit for earth boring drills comprising cylindrical toothed cutters with difierent diameters on axes inclined upwardly and outwardly and at an acute angle to each other and being all disposed in a group to one side of the drill axis.

35. A roller cutter organization for earth boring drills having a side cutter near the outer wall oithe' drill on an axis inclining upwardly and outwardly, and an additional cutter between the side cutter and. the vertical axis oi the drill,

"said additional cutter being on an axis inclined upwardly and outwardly and extending in the same general direction as the axis oi the side cutter, said cutter being eccentrically arranged relative to the side cutter and of a smaller diameter than the side cutter,'said additional cutter and said side cutter rotating in planes converging upwardly in the bit head. I

36. A roller cutter unit for earth boring drills comprising cutters positioned side by side forming a group extending from the axis at the unit other and all in a group on the same side at the vertical axis of the drill, the larger diameter cutter being for cutting an area of the bottom of the hole adjacent the side thereof, the lowermost portions of the peripheries of said cutters being at substantially the same distance from the plane 5 of the axis of the'side cutter.

38. A roller cutter organization for earth boring drills having a side cutter disposed at the side wall of the drill for cutting an annular path only at the side of the hole and rotating on an axis inclining upwardly and outwardly, and an additional cutter between the side cutter and the vertical axis of the drill, said additional cutter being on an axis inclined upwardly and outwardly, said cutter being eccentrically arranged relative to the side cutter and of a smaller diameter than the side cutter, said smaller diameter cutter having the lowermost portion of its periphery at a distance from the prolonged axial line of the side cutter equal substantially to the radius 20 of the side cutter, said cutters rotating in planes convergent upwardly toward the drill axis, substantially as described.

39. In combination in an earth boring drill, a bit head, a roller cutter organization comprising 25 a plurality of rotary cutters disposed in a group to one side of the drill axis and all arranged side by side in planes inclined to the horizontaland convergent upwardly in the bit head, said cutters cutting entirely on the bottom of the hole below 30 the drill from substantially the drill axis to beyond the bit head to provide clearance therefor.

iii. A spindle assembly for roller cutter means of earth boring drills comprising spindles interhtting together at their ends, said spindles having a terminal flange like head portion at one end and a cylindrical bearing surface at the other end, said head portion having at each side thereof end-thrust receiving surfaces and said head portion having in its outer face a bearing socket receiving the end of the adjacent spindle.

ii. A spindle assembly according to claim 40 in which the axis of said bearing socket is inclined to the axis of the cylindrical bearing ing an integral flange portion intermediate bearing portions, said bearing portions being arranged eccentric to each other and having axes at an acute angle to each other, the sides of said flange portion having surfaces receiving the end thrust oi adjacent roller cutters and roller cutters of different diameters on said bearing portions.

it. A roller cutter unit comprising a group of substantially cylindrical cutters, positioned side by side and cutting the entire area at the bottom of the hole, spindles for the cutters, each cutter oi the group. contacting the bottom of thehole below the drill and the cutter axes being inclined 60 at an acute angle to the vertical and also to the axis oi each of the other cutters.

All. A roller cutter organization for rotary earth 1 boring drills comprising a plurality oi independently rotatable cutters arranged all to one side of the axis or the organization'with their axes in the same vertical radial plane, with the outermost roller cutter oi larger diameter than the said spindles having an interfltting connection with each other between said flange and spindle portions, said spindle portions being arranged eccentrically relative to each other and on axes at an acute angle to each other, a roller cutter on each bearing portion, each cutter finding an end thrust bearing on the flange, and roller bearings between each cutter and its spindle portion, said roller bearings finding end thrust bearings against the side face of said flange.

46. A spindle for mounting in an earth boring drill comprising end cylindrical bearing portions upon which cutters may turn and an intermediate flange portion, the axes of said bearing portions being disposed at an acute angle relative to each other, and also being laterally offset relative to each other, the sides of said flange being perpendicular to the axis of the adjacent bearing portion to provide end thrust surfaces.

47. A rotary toothed cutter unit for earth boring drills having a side cutter mounted for cutting an area at the side of a hole including clearance for the bit head and inclining upwardly and inwardly towards the vertical axis of the unit and an independently rotatable inclined cutter between the side cutter and the vertical axis of the unit on an axis at an acute angle to that of the side cutter and cutting in a plane below the side cutter, the sides of all of said cutters facing toward each other, substantially as described.

48. Aroller cutter organization for earth boring drills comprising a cutter located adjacent the axis of the drill, a side cutter mounted for cutting an area at the Side of a, hole including clearance for the bit head, and a cutter intermediate the side cutter and the cutter first mentioned, said intermediate and side cutters contacting the bottom of the hole below the drill and being on axes inclining upwardly and outwardly at an acute angle to each other, the sides of all of said cutters facing toward each other.

49. An earth boring drill comprising a bit head and a plurality of independently revoluble cylindrical peripherally toothed cutters of different diameters arranged side by side with their axes in the same vertical plane at an acute angle to each other, the larger diameter cutter being disposed at the side of the bit head for cutting an area of the bottom of the hole adjacent the side thereof, and the smaller diameter cutter being between the side cutter and the bit axis, the lowermost portions of the peripheries of said cutters being at substantially the same distance from the plane of the axis of the side cutter.

50. An earth boring drill comprising a bit head and a plurality of independently revoluble cylindrical peripherally toothed cutters. of difierent diameters arranged side by side with their axes in the same vertical plane at an acute angle to each other, and inclined upwardly and outwardly, the larger diameter cutter being disposed at the side of the bit head for cutting an area of the bottom of the hole adjacent the side thereof, the smaller diameter cutter being between the side cutter and the bit axis, the lowermost portions of the peripheries of said cutters being at substantially the same distance from the plane of the axis of the side cutter.

51. An earth boring drill comprising three rotary side cutter means spaced apart about the drill axis and tracking an annular area at the side of the bore hole including clearance for the drill, one of the side cutter means having associated therewith rotatable means lying axially in the same vertical plane as the axis of the associated side cutter means, said rotatable means having non-true rolling teeth cutting the area within the annular area cut by the side cutters.

52. An earth boring drill according to claim 51 in which the side cutter with which the said rotatable means is associated, is rotatable independently of the rotatable means.

53. An earth boring drill comprising two rotary toothed cutting means disposed with their axes inclining downwardly and inwardly in different vertical planes intersecting the vertical axis of the drill, for cutting an annular area at the side of the bottom of the hole and clearance for the drill, other rotary cutting meansdisposed axially in a vertical plane intersecting the drill axis and spaced apart 120 from the vertical planes first mentioned, said other cutting means in part substantially tracking the two rotary cutting means first mentioned and additionally cutting the entire area at the bottom of the hole within the said annular area, all of the cutting teeth having non-true rolling action on the formation at the bottom of the hole.

54. An earth boring drill according to claim 53 in which said last mentioned rotary cutting means decreases in diameter inwardly towards the vertical axis of the drill.

55. An earth boring drill comprising a bit head supporting three spindles inclining downwardly and inwardly toward the drill axis; the axes of said spindles lying in planes coincident with the drill axis and spaced 120 apart, three rotary side cutter means mounted on the respective spindles and tracking an annular area along the bottom and side wall of the bore hole including clearance for the drill, roller cutter means supported by the bit head, and positioned to cut the area at the bottom of the bore hole intermediate the annular area cut by the side cutter means, said roller cutter means lying axially in the same vertical plane as the axis of one of the side cutter means, all of said side cutter means and roller cutter means having cutting teeth arranged to engage the bottom of the bore hole with a nontrue-rolling action.

CLARENCE E. REED. 

